2 Answers
2

This problem usually occurs when your nvidia drivers are not installed properly. Usually it is the result of installing the drivers from nvidia's website before or after the drivers that you get from the Ubuntu repositories (which is the recommended source, I might add).

To solve this, you need to remove the driver (if you installed it using the run file, you can uninstall it using the same file (see below)).

Or, you can delete the libraries associated with it (my apologies as I'm not on my nvidia powered laptop at the moment so I cannot check for certain as to which files you have to remove).

If you installed from nvidia's website, you can remove the drivers using: